Cooling system for combustion engines



March 8, 1938. s. w. BJGRKSTRGM 2,110,497

COOLING SYSTEM FOR COMBUSTION ENGINES Filed Aug. 12, 1956 Patented Mar. '8, 1938 UNITED STATES PATENT OFFlCE Gustaf WValdemar Bjiirkstrom, Stockholm, Sweden Application August 12,

1936, Serial No. 95,641

In Sweden August 17, 1935 9 Claims.

The invention relates to combustion engines, more particularly to a cooling system of the type in which the cooling fluid circulates through the cooling jacket of the engine and a mixing chamher which is connected to a pump supplying additional cooling fluid to be mixed with the circulating cooling liquid to cool the same, and which mixing chamber is provided with an outlet for the heat surplus cooling fluid.

Usually the engine, as for instance of a boat, is cooled by water pumped into the cooling jacket directly from the sea, the cylinder becoming cooled at the bottom to substantially the temperature of the cooling water, but in order to correspond as closely as possible to the middle cooling suitable to the combustion temperature it must obtain at the topthereof a considerably high tempera ture which causes heat stresses in the walls of the engine cylinder and the power of the engine.

One object of the invention is to overcome this drawback and to provide a cooling system in which the'various parts of the cylinder are cooled to the correct extent at normal engine speed as well as at light running.

According to an essential feature of the invention the mixing chamber is provided with a baffle device situated between the inlet for the additional cooling fluid and the outlet for the surplus cooling fluid. Such baille device assists in effecting a satisfactory mixing of the additional fluid and the circulating fluid and further it provides a means for separating the heat surplus fluid which is to be drawn-off from the mixing chamber or alternately be carried to a radiator for cooling purposes.

According to another feature of the invention the mixing chamber is connected to the outlet and the inlet of the coolingjacket of the engine so as to causethe cooling fluid to pass, due to the thermosiphon action, through the cooling jacket and the mixing chamber. I

Due to the heat supplied from the cylinder when the cooling water is circulating at normal speed, the cooling water pumped into the cylinder is to be mixed intimately with the water escaping from the cooling jacket and thus must not form a stream which will pass unmixed through the water mass of the mixing chamber. To this end the mixing chamber according to the invention is given a suitable shape and is furnished with a nozzle having a certain area of passage and such a direction that the cooling water is injected in the shape of a jet which effects a helical motion and a mixing of the water mass partly by a certain velocity, partly by a given direction and partly by means of guide vanes.

When the motor is operating at reduced power or is running light the power of the water pump is reduced to such a considerable extent that where no particular steps were taken the water flow would not be in proportion to the heat supply from the engine cylinder and therefore the engine would become too hot. At a low number of revolutions the flow through the nozzle will be reduced to an immaterial jet which is naturalized immediately in the water mass. The fact that the hot water tends to ascend and the cooled water to descend is utilized in the present invention in such a manner that the mixing chamber is formed with a channel, at which the pipe to the cooling jacket begins and which is given such aposition that the weak cold water fiow from the nozzle is kept separated from the remainder of the water in the mixing chamber, follows the natural circulation inthis channel and cools in this way directly the water supply to the cooling jacket, whereby the engine cylinder obtains the cooling required to maintain the engine at a suitable temperature, even when the engine operates at reduced power and at a low number of revolutions. For the control of the cooling water quantity from the pump a cock is suitably arranged to control the flowing-in quantity of the additional water to be mixed with the circulating coolin liquid.

The invention is illustrated in the accompanying drawing'which shows an embodiment of the cooling system. Fig. l is a side elevation of an engine provided witha mixing chamber. Fig. 2 is an end view or" the same arrangement as that shown in Fig. l but having the cover of the mixing chamber removed. Fig. 3 is a section after lines AA in Fig. 2 and B-B in Fig. 7, showing an assemblage of the mixing chamber. Fig. 4 shows a detail of the cover of the mixing chamber, shown in a top'view as compared with Fig. 3. Fig. 5 shows the cover of the mixing chamber in the same position as that shown in Fig. 4 but looking towards the front thereof. Fig. 6 is a section on line C-C of Fig. '7 showing a detail of the cover of the mixing chamber and an embodiment of a tubular baffle arranged adjustably and surrounded by a helical guide vane. Fig. 7 is a top view of the same arrangement as that shown in Fig. 6. Fig. 8 is a sectional view on line DD in Fig. 6 showing the tubular baffle device as seen from the front thereof. Fig. 9 is a section through the mixing chamber along EE in Fig. 1 on an enlarged. scale.

The drawing illustrates an embodiment, in which the outlet of the engine cylinder I for the cooling water coming from the jacket is connected by'a chamber 2A and a flange 2 to the mixing chamber 3A, 6 having a cover 4. The chamber 3A, 6 is shaped in the presentcase as a horizontal cylinder the axis of which is directed to the flow direction of the water coming from the engine jacket and for mixing the cooling water is provided with a bafile 5 separating a chamber 6 which is connected by a; channel 'l'with the pipe 8 for the cooling water outlet and further with the channel 9 which is. suitably positioned at one end of the cylindric portion. Said channel 9 is arranged soas to easily receive water' in the direction of flow or a. direction being tangential to the direction of flow of the water in the mixing chamber ,3. The passage 9 is connected by a pipe ID to the inlet of the cylinder jacket.

The cylinder 3A is furnished at the end opposite to the passage 9 with a nozzle II provided tangentially in relation to the wall of the cylinder 3A and connected bya pipe I2 with an adjusting cock I3 having a lever I3A and connected also to the water pump I4 which is driven in the present case from the crank shaft of the engine. The nozzle is provided with an outlet IIA having a passage area suited for a water jet. The pump I4 is connected to a suction pipe I5 and control cock I3 with an outlet pipe I6. In the present case the cover 4is positioned adjacent to the nozzle II for the cooling water supply and fur-. nished with a helically shaped surface I! disposed in the direction of the water jet from the nozzle II and adapted as a guide for the water flow;

said surface terminates at 18 in a surface I9 suitably arranged at right angles to the cover 4. Furthermore, the cover- 4 comprises a tubular baflle 20 in the present case being adjustable relatively to the cover 4. by a bolt 20Aand a nut 20B and having its axis directed in the same sense as the axis of the cylinder 3A; the baflle has such a position that a portion of the water from the cylinder jacket I flows into its inlet opening. At'the end opposite to the inlet the baflie 2D is provided in the present case with a passage 2| which is disposed adjacent to the guide surface I'I, I8 of the cover 4. Furthermore, the bafile 20 is provided at the outer wallthereof with a helical guide vane 22. The bafiie wall 5 is suitably provided with a passage'23 to discharge the air or possible steam'blisters escaping from the mixing chamber 3A. In the present case the 1 chamber 2A disposed above the engine cylinder is formed with a suitable shape and a sufficient height and passage area to effect the separation of the superheated water which is to be separated from the colder portion of the water mass.

As shown in the drawing the cooling water circulates in the direction of the arrow. The water escaping from the cooling jacket of the cylinder I is divided in the chamber 2A into superheated and colder water the former flowing as shown by the arrow 24 above the battle 5 and the latter as shown by the arrows 25 and 25A below the baffle 5. The portion of the water separated above the battle 5 is mixed to a great extent with steam blisters and is discharged through the outlet 1, 8. The water below the baflle 5 is mixed in the mixing cylinder 3A with the water jet and is imparted circulation thereby in the direction of the arrow 26 from the nozzle II which is connected by the pipe I2 and the cock I3 to the pump I4 and the suction pipe I5, and'which continues as ,shown by the arrow 28 through the channel -9- and the pipe III back to'the cooling jacket of the cylinder I. The water from the nozzle II is caused to move in a helical path partly by the disposition of the tubular baflle 20 in the mixing chamber and partly by the helical guide surface II, I8 of the cover 4 and the helical guide .vane 22 of the baffle 20 so that the water obtains a motion as shown by the arrows 21, 21A, 21B. The

water obtaining the direction of flow as shown by I the arrows 25A and passing through the baflle '20 continues, due to the suction effect of the circulation behind thesurface I9 of the cover 4, through the passage 2I and is associated with the water escaping from the nozzle II. By turning and the baflle 20 being rotatable in relation to the cover 4 and provided with a stop device and formed in the present case as a tube having a base, and the passage2I beneath the projection arranged at the cover 4 for the guide surface I1, I8, in the direction against the surface I9, the

area of the passage 2I may be adjustably controlled for the circulating water quantity from the cylinder jacket. The additional water quantity needed for the cooling is controlled by shitting the lever I3A of the cock I3, and surplus water delivered from the pump is discharged through the tube I6. When the engine is running at a low number of revolutions the water. jet through the nozzle II is reduced to an essential degree so that the helical motion of the water mass will almost cease in the mixing chamber. The cooled water running in will then follow the bottom of the mixing chamber as, shown by the arrow 29, follows'the path of the thermosiphon circulation through the channel 9 of the mixing chamber, and continues together with the portion of the water from the cylinder jacket through the tube ID to the cooling jacket of the cylinder.

Without departing from the spirit of the invention the mixing chamber may have another constructional form than that shown or the arrangement be constructed with a. specially shaped chamber'for separating the superheated water, or provided with more or less complicated baffle system departing from the drawing.

What I claim is:

1. In a cooling system for combustion engines comprising a cooling jacket and a mixing chamher for circulating cooling fluid and a pump for supply of additional cooling fluid to be mixed with the circulating cooling fluid, the combination of an outlet in the upper part of said mixing chamber for surplus cooling fluid, an inlet in said mixing chamber for the additional cooling fluid, a

communication for mixed cooling water between the mixing chamber and the lower portion of the cylinder jacket and baflle means in said mixing chamber situated between said outlet and said inlet to separate the most heated part of the circulating cooling fluid from said cylinder cooling uated between said outlet and said inlet to separate the most heated part of the circulating cooling fluid and a communication for mixed cooling water between the mixing chamber and the lower portion of the cylinder jacket.

cooling fluid, baffle means in said mixing cham- 7 her situated between said outlet and said inlet,

to separate the most heated part of the circulating cooling fluid, a space above said baffle means, a space below said bafile means, and a passage connecting said spaces.

4. In a coo-ling system for combustion engines comprising a cylinder cooling jacket and a mixing chamber for circulating cooling fluid and a pump for supply of additional cooling fluid to be mixed with the circulating cooling fluid, the combination of an outlet from said mixing chamber for surplus cooling fluid, an inlet in said mixing chamber for the additional cooling fluid, baiile means in said mixing chamber situated between said outlet and said inlet, a tubular chamber disposed below said bafile means, said inlet for the additional cooling fluid being tangential to the wall of said tubular chamber.

5. In a cooling system for combustion engines comprising a cylinder cooling jacket and a mixing chamber for circulating cooling fluid and a pump for supply of additional cooling fluid to be mixed with the circulating cooling fluid, the combination of an outlet from said mixing chamber for surplus cooling fluid, an inlet in said mixing chamber for the additional cooling fluid, baflie means in said mixing chamber situated between said outlet and said inlet, a tubular chamber disposed below said bafile means, an end of said tubular chamber arranged with an opening adjacent to said cylinder cooling jacket, said inlet for the additional cooling fluid being tangential to the Wall of said tubular chamber, a helical guide surface disposed at one end of said tubular chamber adjacent to said tangential inlet and associated with an axial surface.

6. In a cooling system for combustion engines comprising a cylinder cooling jacket and a mixing chamber for circulating cooling fluid and a pump for supply of additional cooling fluid to be mixed with the circulating cooling fluid, the combination of an outlet from said mixing chamber for surplus cooling fluid, an inlet in said mixing chamber for the additional cooling fluid, bailie means in said mixing chamber situated between said outlet and said inlet, a tubular chamber disposed below said bafile means, said tubular chamber consisting of a horizontal cylindric chamber,

, tangentially to said horizontal chamber to cause the circulating cooling fluid to pass therethrough.

7. In a cooling system for combustion engines comprising a cylinder cooling jacket and a mixing chamber for circulating cooling fluid and a pump for supply of additional cooling fluid to be mixed with the circulating cooling fluid, the combination of an outlet from said mixing chamber for surplus cooling fluid, an inlet in said mixing chamber for the additional cooling fluid, baflie means situated in said mixing chamber between said outlet and said inlet, a cylindric chamber disposed below said bafiie means, a tubular bailie arranged coaxially in said cylindric chamber, a radial passage in said tubular baffle, said bafile and said passage being adapted to receive and guide a portion of the circulating cooling fluid escaping from said cylinder cooling jacket.

8. In a cooling system for combustion engines comprising a cylinder cooling jacket and a mixing chamber for circulating cooling fluid and a pump for supply of additional cooling fluid to be mixed with the circulating cooling fluid, the combination of an outlet from said mixing chamber for surplus cooling fluid, an inlet in said mixing chamber for the additional cooling fluid, baflle means in said mixing chamber situated between said outlet and said inlet, a cylindric chamber disposed below said baffle means, a tubular baille coaxially and rotatably arranged in relation to said cylindric chamber, a radial passage in said tubular battle and a surface of said cylindric chamber adapted to cooperate with the mouth of said radial passage to increase or decrease the area thereof in turning said tubular bafile.

9. In a cooling system for combustion engines comprising a cylinder cooling jacket and a mixing chamber for circulating cooling fluid and a pump for supply of additional cooling fluid to be mixed with the circulating cooling fluid, the combination of an outlet from said mixing chamber for surplus cooling fluid, an inlet in said mixing chamber for the additional cooling fluid,'bafile means in said mixing chamber situated between said outlet and said inlet, a cylindric chamber disposed below said baffle means, one end of said cylindric chamber provided with helical guide surface associated with an axial surface, said inlet for the additional cooling fluid tangentially arranged with the wall of said cylindric chamber and situated adjacent to said one end of said cylindric chamber, a tubular baffle with radial passage arranged coaxially in said cylindric chamber, and a helical guide vane surrounding said tubular baille.

GUSTAF WALDEMAR BJCSRKsTRM. 

